Video encoding method, video decoding method, video encoding apparatus, and video decoding apparatus

ABSTRACT

A video encoding method of performing scalable encoding on input video includes: determining a total number of layers of the scalable encoding to be less than or equal to a maximum layer count determined according to a frame rate; and performing the scalable encoding on the input video to generate a bitstream, using the determined total number of layers.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a continuation application of PCT International Application No.PCT/JP2014/002974 filed on Jun. 4, 2014, designating the United Statesof America, which is based on and claims priority of U.S. ProvisionalPatent Application No. 61/831,209 filed on Jun. 5, 2013. The entiredisclosures of the above-identified applications, including thespecifications, drawings and claims are incorporated herein by referencein their entirety.

FIELD

One or more exemplary embodiments disclosed herein relate to a videoencoding method of encoding video or a video decoding method of decodingvideo.

BACKGROUND

The technique disclosed in Non Patent Literature (NPL) 1 is a techniquerelated to a video encoding method of encoding video (including a movingpicture) and a video decoding method of decoding video (including amoving picture). The rule disclosed in NPL 2 is a rule for practicerelated to encoding and decoding.

CITATION LIST Non Patent Literature

-   [NPL 1] Joint Collaborative Team on Video Coding (JCT-VC) of ITU-T    SG16 WP3 and ISO/IEC JTC1/SC29/WG11 12th Meeting: Geneva, CH, 14-23    Jan. 2013 JCTVC-L1003_v34.doc, High Efficiency Video Coding (HEVC)    text specification draft 10 (for FDIS & Last Call)    http://phenix.it-sudparis.eu/jct/doc_end_user/docurnents/12_Gene    va/wg11/JCTVC-L1003-v34.zip-   [NPL 2] Association of Radio Industries and Businesses, ARIB    Standard STD-B32 Ver. 2.8, 2-STD-B32v2_8.pdf: “Video Coding, Audio    Coding and Multiplexing Specifications for Digital Broadcasting”    http://www.arib.or.jp/english/html/overview/doc/2-STD-B32v2_8.pdf

SUMMARY Technical Problem

However, there are cases where ineffective processing is used in aconventional video encoding method or video decoding method.

Thus, one non-limiting and exemplary embodiment provides a videoencoding method of efficiently encoding video or a video decoding methodof efficiently decoding video.

Solution to Problem

In one general aspect, the techniques disclosed here feature a videoencoding method of performing scalable encoding on video, whichincludes: determining a total number of layers of the scalable encodingto be less than or equal to a maximum layer count determined accordingto a frame rate of the video; and performing the scalable encoding onthe video to generate a bitstream, using the total number of layersdetermined.

In one general aspect, the techniques disclosed here feature a videodecoding method of decoding a bitstream obtained by performing scalableencoding on video, which includes: decoding the video in the bitstream;decoding first information in the bitstream, the first informationindicating a total number of layers of the scalable encoding; andreordering, using the total number of layers indicated in the firstinformation, pictures included in the video decoded, and outputting thepictures reordered, wherein the total number of layers is less than orequal to a maximum layer count predetermined according to a frame rateof the bitstream.

These general and specific aspects may be implemented using a system, amethod, an integrated circuit, a computer program, or acomputer-readable recording medium such as a CD-ROM, or any combinationof systems, methods, integrated circuits, computer programs, orcomputer-readable recording media.

Advantageous Effects

One or more exemplary embodiments or features disclosed herein provide avideo encoding method by which video can be efficiently encoded or avideo decoding method by which video can be efficiently decoded.

BRIEF DESCRIPTION OF DRAWINGS

These and other advantages and features will become apparent from thefollowing description thereof taken in conjunction with the accompanyingDrawings, by way of non-limiting examples of embodiments disclosedherein.

FIG. 1 illustrates an example of an encoding configuration.

FIG. 2 illustrates a display latency picture count.

FIG. 3 is a block diagram of a video encoding apparatus according toEmbodiment 1.

FIG. 4 is a flowchart of a video encoding process according toEmbodiment 1.

FIG. 5 is a block diagram of a limit setting unit according toEmbodiment 1.

FIG. 6 is a flowchart of a limit setting process according to Embodiment1.

FIG. 7 is a block diagram of an encoding unit according to Embodiment 1.

FIG. 8 is a flowchart of an encoding process according to Embodiment 1.

FIG. 9A illustrates an output latency picture count according toEmbodiment 1.

FIG. 9B illustrates an output latency picture count according toEmbodiment 1.

FIG. 9C illustrates an output latency picture count according toEmbodiment 1.

FIG. 9D illustrates an output latency picture count according toEmbodiment 1.

FIG. 10 illustrates an example of an encoding configuration limitaccording to Embodiment 1.

FIG. 11A illustrates an encoding configuration according to Embodiment1.

FIG. 11B illustrates an encoding configuration according to Embodiment1.

FIG. 11C illustrates an encoding configuration according to Embodiment1.

FIG. 11D illustrates an encoding configuration according to Embodiment1.

FIG. 12A illustrates a display latency picture count according toEmbodiment 1.

FIG. 12B illustrates a display latency picture count according toEmbodiment 1.

FIG. 12C illustrates a display latency picture count according toEmbodiment 1.

FIG. 12D illustrates a display latency picture count according toEmbodiment 1.

FIG. 13 is a block diagram of a video decoding apparatus according toEmbodiment 2.

FIG. 14 is a flowchart of a video decoding process according toEmbodiment 2.

FIG. 15 is a flowchart of a video encoding method according toEmbodiment 1.

FIG. 16 is a flowchart of a video decoding method according toEmbodiment 2.

FIG. 17 illustrates an overall configuration of a content providingsystem for implementing content distribution services.

FIG. 18 illustrates an overall configuration of a digital broadcastingsystem.

FIG. 19 is a block diagram illustrating an example of a configuration ofa television.

FIG. 20 is a block diagram illustrating an example of a configuration ofan information reproducing/recording unit that reads and writesinformation from and on a recording medium that is an optical disk.

FIG. 21 illustrates an example of a configuration of a recording mediumthat is an optical disk.

FIG. 22A illustrates an example of a cellular phone.

FIG. 22B is a block diagram illustrating an example of a configurationof a cellular phone.

FIG. 23 illustrates a structure of multiplexed data.

FIG. 24 schematically illustrates how each stream is multiplexed inmultiplexed data.

FIG. 25 illustrates how a video stream is stored in a stream of PESpackets in more detail.

FIG. 26 illustrates a structure of TS packets and source packets in themultiplexed data.

FIG. 27 illustrates a data structure of a PMT.

FIG. 28 illustrates an internal structure of multiplexed datainformation.

FIG. 29 illustrates an internal structure of stream attributeinformation.

FIG. 30 illustrates steps for identifying video data.

FIG. 31 is a block diagram illustrating an example of a configuration ofan integrated circuit for implementing the moving picture coding methodaccording to each embodiment.

FIG. 32 illustrates a configuration for switching between drivingfrequencies.

FIG. 33 illustrates steps for identifying video data and switchingbetween driving frequencies.

FIG. 34 illustrates an example of a look-up table in which video datastandards are associated with driving frequencies.

FIG. 35A illustrates an example of a configuration for sharing a moduleof a signal processing unit.

FIG. 35B illustrates another example of a configuration for sharing amodule of the signal processing unit.

DESCRIPTION OF EMBODIMENTS

Underlying Knowledge Forming Basis of the Present Disclosure

The inventors found that the following problem arises in the videoencoding apparatus that encodes video or the video decoding apparatusthat decodes video, described in the “Background” section.

Recent years have seen significant technology advancement of digitalvideo devices, leading to increased opportunities for compressing andencoding video signals output from video cameras or television tuners (aplurality of chronologically arranged pictures) and recording resultantencoded signals onto recording media such as digital versatile discs(DVDs) or hard disks.

There has been H. 264/AVC (MPEG-4 AVC) video coding standard. As anext-generation standard, a high efficiency video coding (HEVC) standardhas been considered (NPL 1). A rule for practice of the video codingstandard has also been considered (NPL 2).

In the current rule for practice (NPL 2), the encoding configuration islimited up to three layers as illustrated in FIG. 1, and thus themaximum display latency picture count is limited to two as illustratedin FIG. 2. TemporalId in FIG. 1 is an identifier of a layer in theencoding configuration. TemporalId having a larger value indicates adeeper layer.

Each square block represents a picture; I_(X) in a block indicates thatthe block represents an I-picture (an intra-frame prediction picture),P_(X) in a block indicates that the block represents a P-picture (aforward reference prediction picture), and B_(X) in a block indicatesthat the block represents a B-picture (a bi-directional referenceprediction picture). The sign _(X) of I_(X), P_(X), and B_(X) indicatesa display order, that is, a place of the corresponding picture in thesequence in which the pictures are displayed.

An arrow between the pictures indicates a reference relationship. Forexample, a prediction image for a picture B₁ is generated using apicture I₀, a picture B₂, and a picture P₄ as reference pictures. Theuse of a picture having TemporalId larger than TemporalId of a referencesource picture as a reference picture is prohibited. Thus, the sequencein which the pictures are decoded is an ascending order of TemporalId asillustrated in FIG. 2, that is, the following order: the picture I₀, thepicture P₄, the picture B₂, a picture B₁, and a picture B₃.

Providing layers allows a bitstream to be given temporal scalability.

For example, in order to obtain 30 frames per second (fps) video from a60 fps bitstream, the video decoding apparatus decodes only pictureshaving TemporalId of 0 and TemporalId of 1 illustrated in FIG. 1. Bydoing so, the video decoding apparatus can obtain 30 fps video. Sincedecoded video needs to be output without blanks in the sequence, thevideo decoding apparatus outputs pictures in sequence from the pictureI₀ after decoding the picture B₂. Consequently, the display latencypicture count is two. When this count is converted into time, thedisplay latency is 2/30 seconds where the original frame rate is 30 fps,and the display latency is 2/60 seconds where the original frame rate is60 fps.

The use of a configuration having high temporal scalability makes itpossible that when a frequency band is crowded or when a video decodingapparatus having low processing capacity performs a decoding process,the video decoding apparatus decodes only pictures in a layer having asmall TemporalId and display resultant video. Thus, the versatility isenhanced. However, tolerance to a large number of layers in theconfiguration presents a problem in that the display latency increases.

Even when the display latency picture count is predetermined asdescribed above, the display latency varies depending on frame rate.When the frame rate is lower (e.g., 24 fps) than a standard frame rate(e.g., 30 fps), the display latency is 2/24 seconds, that is, longerthan 2/30 seconds that is latency at 30 fps.

According to an exemplary embodiment disclosed herein, a video encodingmethod of performing scalable encoding on video includes: determining atotal number of layers of the scalable encoding to be less than or equalto a maximum layer count determined according to a frame rate of thevideo; and performing the scalable encoding on the video to generate abitstream, using the total number of layers determined.

By doing so, the video encoding method makes it possible to increase thenumber of layers while reducing an increase in the display latency.Thus, in the video encoding method, the video can be efficientlyencoded.

For example, the maximum layer count may be less than or equal to fourwhen the frame rate is less than or equal to 60 frames per second (fps).

For example, the maximum layer count may be five when the frame rate is120 fps.

For example, it may be that the video encoding method further includes:determining a picture type of a picture included in the video, to make adisplay latency picture count less than or equal to a maximum picturecount determined according to the frame rate, the display latencypicture count being a total number of decoded pictures waiting for beingoutputted in a video decoding apparatus, and in the performing, thevideo is encoded as pictures each having the picture type determined.

For example, in the determining of a picture type, the picture type ofthe picture may be determined to make a continuous B-picture count lessthan or equal to a maximum continuous count determined according to theframe rate, the continuous B-picture count being a total number ofpictures in a B-picture group that only includes B-pictures.

For example, it may be that the maximum picture count, an encoder outputlatency from when the video is input to a video encoding apparatus towhen the bitstream is output, and the frame rate are defined byMaximum picture count=int(log₂(encoder output latency [s]×frame rate[fps])),

the maximum continuous count, the encoder output latency, and the framerate are defined byMaximum continuous count=int(encoder output latency [s]×frame rate[fps]−1), and

the maximum layer count, the encoder output latency, and the frame rateare defined byMaximum layer count=int(log₂(encoder output latency [s]×frame rate[fps]))+1.

For example, it may be that a maximum picture count [i] in each layer,the encoder output latency, and the frame rate are defined byMaximum picture count [i]=int(log₂(encoder output latency [s]×frame rate[fps]/2^((n-i)))), and

a maximum continuous count [i] in each layer, the encoder outputlatency, and the frame rate are defined byMaximum continuous count [i]=int(encoder output latency [s]×frame rate[fps]/2^((n-i))−1)

where i is an integer less than or equal to the maximum layer count andrepresents a layer, and n represents (the maximum layer count−1).

According to an exemplary embodiment disclosed herein, a video decodingmethod of decoding a bitstream obtained by performing scalable encodingon video includes: decoding the video in the bitstream; decoding firstinformation in the bitstream, the first information indicating a totalnumber of layers of the scalable encoding; and reordering, using thetotal number of layers indicated in the first information, picturesincluded in the video decoded, and outputting the pictures reordered,wherein the total number of layers is less than or equal to a maximumlayer count predetermined according to a frame rate of the bitstream.

By doing so, the video decoding method makes it possible to decode abitstream obtained by efficiently encoding video.

For example, the maximum layer count may be less than or equal to fourwhen the frame rate is less than or equal to 60 fps.

For example, the maximum layer count may be five when the frame rate is120 fps.

For example, it may be that further in the decoding of firstinformation, second information in the bitstream is decoded, the secondinformation indicating a display latency picture count which is a totalnumber of decoded pictures waiting for being outputted in a videodecoding apparatus, and in the reordering, the pictures included in thevideo decoded are reordered using the total number of layers indicatedin the first information and the display latency picture count indicatedin the second information, and the pictures reordered are output.

For example, it may be that further in the decoding of firstinformation, third information in the bitstream is decoded, the thirdinformation indicating a continuous B-picture count which is a totalnumber of pictures in a B-picture group that only includes continuousB-pictures, and in the reordering, the pictures included in the videodecoded are reordered using the total number of layers indicated in thefirst information, the display latency picture count indicated in thesecond information, and the continuous B-picture count indicated in thethird information, and the pictures reordered are output.

For example, it may be that a maximum picture count predeterminedaccording to the frame rate, an encoder output latency from when thevideo is input to a video encoding apparatus to when the bitstream isoutput, and the frame rate are defined byMaximum picture count=int(log₂(encoder output latency [s]×frame rate[fps])),

a maximum continuous count predetermined according to the frame rate,the encoder output latency, and the frame rate are defined byMaximum continuous count=int(encoder output latency [s]×frame rate[fps]−1), and

the maximum layer count, the encoder output latency, and the frame rateare defined byMaximum layer count=int(log₂(encoder output latency [s]×frame rate[fps]))+1.

For example, it may be that a maximum picture count [i] in each layer,the encoder output latency, and the frame rate are defined byMaximum picture count [i]=int(log₂(encoder output latency [s]×frame rate[fps]/2^((n-i)))), and

a maximum continuous count [i] in each layer, the encoder outputlatency, and the frame rate are defined byMaximum continuous count [i]=int(encoder output latency [s]×frame rate[fps]/2^((n-i))−1)

where i is an integer less than or equal to the maximum layer count andrepresents a layer, and n represents (the maximum layer count−1).

According to an exemplary embodiment disclosed herein, a video encodingapparatus that encodes video includes: processing circuitry; and storageaccessible from the processing circuitry, wherein using the storage, theprocessing circuitry performs the video encoding method.

This allows the video encoding apparatus to increase the number oflayers while reducing an increase in the display latency. Thus, thevideo encoding apparatus is capable of efficiently encoding video.

According to an exemplary embodiment disclosed herein, a video decodingapparatus that decodes a bitstream obtained by encoding video includes:processing circuitry; and storage accessible from the processingcircuitry, wherein using the storage, the processing circuitry performsthe video decoding method.

This allows the video decoding apparatus to decode a bitstream obtainedby efficiently encoding video.

These general and specific aspects may be implemented using a system, amethod, an integrated circuit, a computer program, or acomputer-readable recording medium such as a CD-ROM, or any combinationof systems, methods, integrated circuits, computer programs, orcomputer-readable recording media.

Hereinafter, embodiments are specifically described with reference tothe Drawings. Each of the embodiments described below shows a specificexample. The numerical values, shapes, materials, structural elements,the arrangement and connection of the structural elements, steps, theprocessing order of the steps etc. shown in the following embodimentsare mere examples, and therefore do not limit the scope of the appendedClaims and their equivalents. Therefore, among the structural elementsin the following embodiments, structural elements not recited in any oneof the independent claims representing the broadest concepts aredescribed as arbitrary structural elements.

Embodiment 1

A video encoding apparatus according to the present embodiment increasesthe number of layers when a frame rate is high. This makes it possibleto increase the number of layers while reducing an increase in thedisplay latency.

<Overall Structure>

FIG. 3 is a block diagram illustrating a structure of a video encodingapparatus 100 according to the present embodiment.

The video encoding apparatus 100 illustrated in FIG. 3 generates abitstream 155 by encoding input video 153. This video encoding apparatus100 includes a limit setting unit 101 and an encoding unit 102.

<Operation (Overall)>

Next, a flow of an overall encoding process is described with referenceto FIG. 4. FIG. 4 is a flowchart of a video encoding method according tothe present embodiment.

First, the limit setting unit 101 sets an encoding configuration limit154 related to an encoding configuration of scalable encoding (S101).Specifically, the limit setting unit 101 sets the encoding configurationlimit 154 using a frame rate 151 and an output latency limit 152.

Next, the encoding unit 102 encodes the encoding configuration limit 154and in addition, encodes the input video 153 using the encodingconfiguration limit 154, to generate the bitstream 155 (S102).

<Structure of Limit Setting Unit 101>

FIG. 5 is a block diagram illustrating an example of an internalstructure of the limit setting unit 101.

As illustrated in FIG. 5, the limit setting unit 101 includes a layercount setting unit 111, a layer count parameter setting unit 112, adisplay latency picture count setting unit 113, a continuous B-picturecount setting unit 114, and a continuous count parameter setting unit115.

<Operation (Setting of Encoding Configuration Limit)>

Next, an example of a limit setting process (S101 in FIG. 4) isdescribed with reference to FIG. 6. FIG. 6 is a flowchart of a limitsetting process according to the present embodiment.

First, the layer count setting unit 111 sets the number of layers or alayer count 161 of the encoding configuration using the frame rate 151and the output latency limit 152 received from outside the videoencoding apparatus 100. For example, the layer count 161 is calculatedby the following Expression 1 (S111).Layer count=int(log₂(output latency limit [s]×frame rate[fps]))+1  Expression 1

In the above Expression 1, int(x) represents a function that returns aninteger to which x is rounded down, and log₂(x) represents a functionthat returns a logarithm of x with respect to base 2. The output latencylimit 152 indicates a maximum length of time from when the input video153 is input to the video encoding apparatus 100 to when the bitstream155 of the input video 153 is output.

Next, using the layer count 161, the layer count parameter setting unit112 sets a layer count parameter 163, that is, sps_max_sub_layers_minus1by the following Expression 2 (S112).sps_max_sub_layers_minus1=Layer count−1  Expression 2

Next, the limit setting unit 101 sets TId to 0 (S113). TId is a variablefor identifying a layer and is used to identify a target layer in eachprocess for subsequent layers.

Next, using the frame rate 151, the output latency limit 152, and thelayer count parameter 163, the display latency picture count settingunit 113 sets a display latency picture count 164 in a layer havingTemporalId of TId (S114). The display latency picture count 164 is thenumber of pictures counted during a picture decoding process, that is,from a start of decoding a picture to a start of displaying the picture.The display latency picture count 164 is calculated by the followingExpression 3.Display latency picture count in layer having TemporalId ofTId=int(log₂(output latency limit [s]×frame rate [fps]/2^((n-TId))))  Expression 3

In the above Expression 3, n represents a maximum TemporalId, that is, avalue of sps_max_sub_layers_minus1 calculated in Step S112. The displaylatency picture count setting unit 113 setssps_max_num_reorder_pics[TId] to the calculated display latency picturecount in the layer having TemporalId of TId.

Next, using the frame rate 151, the output latency limit 152, and thelayer count parameter 163, the continuous B-picture count setting unit114 sets a continuous B-picture count 162 in the layer having TemporalIdof TId (S115). The continuous B-picture count 162 is the number ofpictures in a B-picture group that only includes continuous B-pictures,and is calculated by the following Expression 4.Continuous B-picture count in layer having TemporalId of TId=int(outputlatency limit [s]×frame rate [fps]/2^((n-TId))−1)   Expression 4

Next, using the continuous B-picture count 162 and the display latencypicture count 164 (sps_max_num_reorder_pics[TId]) in the layer havingTemporalId of TId, the continuous count parameter setting unit 115 setsa continuous count parameter 165 in the layer having TemporalId of TId(S116). The continuous count parameter 165 in the layer havingTemporalId of TId is set by the following Expression 5.Continuous count parameter in layer having TemporalId of TId=ContinuousB-picture count in layer having TemporalId ofTId−sps_max_num_reorder_pics[TId]+1  Expression 5

Sps_max_latency_increase_plus1[TId] is set to the calculated continuouscount parameter 165.

Next, the limit setting unit 101 adds 1 to TId so as to change a layerto be processed (S117). Steps S114 to S117 are repeated until TIdbecomes the layer count 161, that is, until processing of all the layersis completed (S118).

Although the limit setting unit 101 herein first sets the layer count161 and then sets the display latency picture count 164 and thecontinuous B-picture count 162 in each layer, the setting sequence isnot limited to this example.

<Structure of Encoding Unit 102>

FIG. 7 is a block diagram illustrating an internal structure of theencoding unit 102. As illustrated in FIG. 7, the encoding unit 102includes a picture reordering unit 121, an encoding block dividing unit122, a subtracting unit 123, a transform/quantization unit 124, avariable-length encoding unit 125, an inverse transform/quantizationunit 126, an adding unit 127, a frame memory 128, an intra predictionunit 129, an inter prediction unit 130, and a selecting unit 131.

<Operation (Encoding)>

Next, an encoding process according to the present embodiment (S102 inFIG. 4) is described with reference to FIG. 8. FIG. 8 is a flowchart ofan encoding process according to the present embodiment.

First, the variable-length encoding unit 125 performs variable-lengthencoding on sps_max_sub_layers_minus1, sps_max_num_reorder_pics[ ], andsps_max_latency_increase_plus1[ ] set by the limit setting unit 101(S121). In each layer, sps_max_num_reorder_pics[ ] andsps_max_latency_increase_plus1[ ] are present, all of which thevariable-length encoding unit 125 encodes.

Next, the picture reordering unit 121 reorders the input video 153 anddetermines picture types of the input video 153 according tosps_max_sub_layers_minus1, sps_max_num_reorder_pics[ ], andsps_max_latency_increase_plus1[ ] (S122).

The picture reordering unit 121 performs this reordering process usingsps_max_num_reorder_pics[sps_max_sub_layers_minus1] andSpsMaxLatencyPictures. SpsMaxLatencyPictures is calculated by thefollowing Expression 6.SpsMaxLatencyPictures=sps_max_num_reorder_pics[sps_max_sub_layers_minus1]+sps_max_latency_increase_plus1[sps_max_sub_layers_minus1]−1  Expression 6

FIG. 9A to FIG. 9D each illustrate this reordering process. Since areordering process such as those illustrated in FIG. 9A to FIG. 9D isperformed, the encoding unit 102 cannot start encoding the input video153 before more than one picture of the input video 153 is input. Thismeans that a lag occurs between input of the first picture of the inputvideo 153 and a start of output of the bitstream 155. This lag is outputlatency. The above-described output latency limit 152 is a limit forthis output latency.

Furthermore, FIG. 9A to FIG. 9D represent an output latency picturecount corresponding to the encoding configuration limit 154. FIG. 9Arepresents the output latency picture count determined wheresps_max_num_reorder_pics[sps_max_sub_layers_minus1] is 1 andSpsMaxLatencyPictures is 2. FIG. 9B represents the output latencypicture count determined wheresps_max_num_reorder_pics[sps_max_sub_layers_minus1] is 2 andSpsMaxLatencyPictures is 3. FIG. 9C represents the output latencypicture count determined wheresps_max_num_reorder_pics[sps_max_sub_layers_minus1] is 3 andSpsMaxLatencyPictures is 7. FIG. 9D represents the output latencypicture count determined wheresps_max_num_reorder_pics[sps_max_sub_layers_minus1] is 4 andSpsMaxLatencyPictures is 15.

For example, in the case of FIG. 9A, a picture 0, a picture 1, a picture2, and a picture 3 are input in this sequence to the video encodingapparatus 100, and the video encoding apparatus 100 encodes the video inthe following sequence: the picture 0, the picture 3, the picture 1, andthe picture 2. The video encoding apparatus 100 needs to seamlesslyoutput the bitstream, and therefore does not start outputting thebitstream until the picture 3 is input. This results in output latencyfor three pictures between input of the picture 0 and a start of outputof the bitstream. Furthermore, the picture reordering unit 121determines a picture type of each picture, and outputs to the interprediction unit 130 information indicating which picture is used as areference picture for the picture. The picture type herein includesI-picture, P-picture, and B-picture.

Next, the encoding block dividing unit 122 divides the input video 153into encoding blocks 171 (S123).

Next, the intra prediction unit 129 generates a prediction block forintra prediction, and calculates a cost for the prediction block (S124).The inter prediction unit 130 generates a prediction block for interprediction, and calculates a cost for the prediction block (S125). Usingthe calculated cost or the like, the selecting unit 131 determines aprediction mode and a prediction block 177 that are to be used (S126).

Next, the subtracting unit 123 calculates a difference between theprediction block 177 and an encoding block 171 to generate a differenceblock 172 (S127). Next, the transform/quantization unit 124 performsfrequency transform and quantization on the difference block 172 togenerate a transform coefficient 173 (S128). Next, the inversetransform/quantization unit 126 performs inverse quantization andinverse frequency transform on the transform coefficient 173 toreconstruct a difference block 174 (S129). Next, the adding unit 127adds the prediction bock 177 and the difference block 174 to generate adecoded block 175 (S130). This decoded block 175 is stored into theframe memory 128 and used in a prediction process by the intraprediction unit 129 and the inter prediction unit 130.

Next, the variable-length encoding unit 125 encodes predictioninformation 178 indicating a used prediction mode or the like (S131) andencodes the transform coefficient 173 (S132).

The processing then proceeds to a next encoding block (S133), and theencoding unit 102 repeats Steps S124 to S133 until processing of all theencoding blocks within the picture is completed (S134).

Subsequently, the encoding unit 102 repeats Steps S122 to S134 untilprocessing of all the pictures is completed (S135).

<Effects>

As described above, the video encoding apparatus 100 according to thepresent embodiment determines an encoding configuration using the framerate 151 and the output latency limit 152. With this, when the framerate 151 is high, the video encoding apparatus 100 can increase layerswithout extending display latency of a decoder and output latency of anencoder, and therefore can increase temporal scalability. Furthermore,an increase in the number of B-pictures can lead to an improvement incompression capabilities.

Furthermore, the display latency of the decoder and the output latencyof the encoder can be controlled so as not to exceed a designated leveleven with various frame rates.

This will be described in more details. FIG. 10 represents the layercount 161, the display latency picture count 164, and the continuousB-picture count 162 calculated using the frame rate 151 and the outputlatency limit 152. In FIG. 10, an example where the output latency limitis 4/30 seconds is shown.

FIG. 11A to FIG. 11D each illustrate an encoding configuration formedbased on the condition represented in FIG. 10. FIG. 11A illustrates aconfiguration with a frame rate of 24 fps. FIG. 11B illustrates aconfiguration with a frame rate of 30 fps. FIG. 11C illustrates aconfiguration with a frame rate of 60 fps. FIG. 11D illustrates aconfiguration with a frame rate of 120 fps.

An output latency picture count of the bitstream is represented in FIG.9A to FIG. 9D where respective frame rates are 24 fps, 30 fps, 60 fps,and 120 fps. FIG. 12A to FIG. 12D illustrate a display latency picturecount determined where respective frame rates are 24 fps, 30 fps, 60fps, and 120 fps.

As illustrated in FIG. 10, the output latency does not exceed the limit,i.e., 4/30 seconds, with all the frame rates. In the current rule forpractice (NPL 2), the encoding configuration is limited up to threelayers as in FIG. 11B. Specifically, the display latency picture countis limited up to two as in FIG. 12B, and the output latency picturecount of the bitstream is limited up to four as in FIG. 9B. With 30 fps,the display latency is 2/30 seconds, and the output latency is 4/30seconds. In the present embodiment, in the case where the output latencylimit has been set to 4/30 seconds, the output latency does not exceed4/30 seconds, and the display latency does not exceed 2/30 seconds, evenwhen the number of layers is increased or decreased according to theframe rate.

Furthermore, in the present embodiment, the video encoding apparatus 100determines an encoding configuration using the limit of the outputlatency rather than the display latency. Thus, when the output latencyis used to limit the encoding configuration, it is possible to determinean encoding configuration so that the display latency and the outputlatency do not exceed 2/30 seconds and 4/30 seconds, respectively, thatis, the display latency and the output latency adopted in the currentrule for practice (NPL 2). More specifically, in the case where thedisplay latency picture count has been determined so that the displaylatency does not exceed 2/30 seconds, that is, the display latency inthe current rule for practice (NPL 2), when the frame rate is 120 fps,the display latency picture count is eight (8/120 seconds) and anencoding configuration having up to nine layers is permitted. However,in the case where the encoding configuration having nine layers is used,the output latency picture count is 256 (256/120 seconds) which is farbeyond the output latency adopted in the current rule for practice (NPL2), i.e., 4/30 seconds. In contrast, in the case where focus is placedon the output latency, that is, the output latency picture count isdetermined so that the output latency does not exceed 4/30 seconds, whenthe frame rate is 120 fps, the output latency picture count is limitedto 16 (16/120 seconds), and the encoding configuration is limited up tofive layers. In this case, the display latency does not exceed 2/30seconds. Thus, it is possible to appropriately limit both the outputlatency and the display latency by limiting the output latency.

Furthermore, the video encoding apparatus 100 sets a limit in each layerfor the encoding configuration. With this, even in a video decodingapparatus that decodes only a picture in a layer having a smallTemporalId, the display latency can be controlled so as not to exceeddesignated time.

Although the video encoding apparatus 100 calculates the encodingconfiguration limit such as the number of layers by the mathematicalexpression in the above description, it may be that a table illustratedin FIG. 10 is stored in a memory in advance and then, with reference tothe table, the video encoding apparatus 100 sets an encodingconfiguration limit associated with the frame rate 151 and the outputlatency limit 152. The video encoding apparatus 100 may use both thetable and the mathematical expression. For example, the video encodingapparatus 100 may set an encoding configuration limit using the tablewhen the frame rate is not greater than 24 fps, and set an encodingconfiguration limit using the mathematical expression when the framerate is greater than 24 fps.

Furthermore, although the video encoding apparatus 100 uses the outputlatency limit 152 and the frame rate 151 received from outside in theabove description, this is not the only example. For example, the videoencoding apparatus 100 may use a fixed value predetermined as at leastone of the output latency limit 152 and the frame rate 151.Alternatively, the video encoding apparatus 100 may determine at leastone of the output latency limit 152 and the frame rate 151 according toan internal state of a buffer memory or the like.

Furthermore, the encoding configurations illustrated in FIG. 11A to FIG.11D are an example and are not the only example. For example, arrowspointing to reference pictures may be different as long as they meet thecondition that a picture having TemporalId larger than TemporalId of areference source picture be not used as a reference picture; forexample, in FIG. 11B, a picture P₄ may be used as a reference picturefor a picture B₁.

The above-described limits for the encoding configuration (the number oflayers, the continuous B-picture count, and the display latency picturecount) are all maximum values, and therefore values smaller than theselimits may be used depending on the situation. As an example, for aframe rate of 30 fps, FIG. 10 represents a total number of layers of 3,a continuous B-picture count of 3[2], and a display latency picturecount of 2[2], which correspond to the encoding configuration in FIG.11B, but the number of layers may be any value not more than 3, and thecontinuous B-picture count and the display latency picture count mayalso be any value corresponding to the number of layers not more than 3.For example, it may be possible that the number of layers is 2, thecontinuous B-picture count is 2[1], and the display latency picturecount is 2[2]. In this case, for example, the encoding configurationillustrated in FIG. 11A is used. Accordingly, in Step S121 of encodingan encoding configuration in FIG. 8, information indicating the encodingconfiguration thus used is encoded.

Furthermore, although sps_max_num_reorder_pics is set to the displaylatency picture count in the above description, sps_max_num_reorder_picsmay be a variable indicating the number of pictures the sequence ofwhich is changed. For example, in the example illustrated in FIG. 9C, apicture 8, a picture 4, and a picture 2 included in input video arereordered and encoded earlier than they are in an input sequence (in adisplay sequence). In this case, the number of pictures the sequence ofwhich is changed is 3, and sps_max_num_reorder_pics may be set to thisvalue 3.

Furthermore, although sps_max_latency_increase_plus1 is set to thecontinuous count parameter, and the value ofsps_max_num_reorder_pics+sps_max_latency_increase_plus1−1(SpsMaxLatencyPictures) is treated as the continuous B-picture count inthe above description, SpsMaxLatencyPictures may represent a maximumvalue of a picture decode count which is the number of pictures decodedbetween when a picture is stored into a buffer after completion ofdecoding of the picture and when the picture becomes ready to bedisplayed. For example, in the case of a picture P₄ in FIG. 12B, thepicture P₄ becomes ready to be displayed after three pictures, a pictureB₂, a picture B₁, and a picture B₃, are decoded following completion ofdecoding of the picture P₄. The picture B₂, the picture B₃, and thepicture P₄ are displayed in sequence. SpsMaxLatencyPictures may be setto this maximum picture decode count, i.e., 3.

Furthermore, although sps_max_num_reorder_pics andsps_max_latency_increase_plus1 are set and encoded for each layer in thepresent embodiment, this is not the only example. For example, in thecase of a system that does not use temporal scalability, only values ofsps_max_num_reorder_pics and sps_max_latency_increase_plus1 in thedeepest layer (a layer having the largest TemporalId) may be set andencoded.

Although the frame rate in the above description has four variations, 24fps, 30 fps, 60 fps, and 120 fps, a frame rate other than thesevariations may be used. Moreover, the frame rate may be a numericalvalue including a decimal, such as 29.97 fps.

Furthermore, the processing in the present embodiment may be executed bysoftware. This software may be distributed via download or the like. Inaddition, this software may be recorded on a recording medium such as acompact disc read only memory (CD-ROM) for distribution. Note that thisapplies to the other embodiments herein.

Embodiment 2

A video decoding apparatus corresponding to the video encoding apparatusdescribed in Embodiment 1 is described in the present embodiment.

<Overall Structure>

FIG. 13 is a block diagram illustrating a structure of a video decodingapparatus 200 according to the present embodiment.

The video decoding apparatus 200 illustrated in FIG. 13 generates outputvideo 263 by decoding a bitstream 251. The bitstream 251 is, forexample, the bitstream 155 generated by the video encoding apparatus 100in Embodiment 1. This video decoding apparatus 200 includes avariable-length decoding unit 201, an inverse transform/quantizationunit 202, an adding unit 203, a frame memory 204, an intra predictionblock generation unit 205, an inter prediction block generation unit206, a limit decoding unit 208, a picture reordering unit 209, and anencoding configuration checking unit 210.

<Operation (Overall)>

Next, a video decoding process according to the present embodiment isdescribed with reference to FIG. 14.

First, the variable-length decoding unit 201 decodes an encodingconfiguration limit 257 in the bitstream 251. This encodingconfiguration limit 257 includes sps_max_sub_layers_minus1,sps_max_num_reorder_pics, and sps_max_latency_increase_plus1. Themeaning of these pieces of information is the same as in Embodiment 1.Next, the limit decoding unit 208 obtains the number of layers by adding1 to sps_max_sub_layers_minus1, obtains a continuous B-picture count bya mathematical expression:sps_max_num_reorder_pics+sps_max_latency_increase_plus1−1, and obtains adisplay latency picture count using sps_max_num_reorder_pics (S201).Furthermore, the limit decoding unit 208 obtains an encodingconfiguration 262 (a total number of layers, a display latency picturecount, and a continuous B-picture count) from sps_max_num_reorder_picsand sps_max_latency_increase_plus1 in a layer having TemporalIdcorresponding to a value of HighestTId 252 received from outside, andoutputs the obtained encoding configuration 262 to the picturereordering unit 209 and the encoding configuration checking unit 210.Here, HighestTId 252 represents TemporalId of the highest layer that isdecoded.

Next, the encoding configuration checking unit 210 checks if each valueof the encoding configuration 262 complies with the rule for practice(S202). Specifically, the encoding configuration checking unit 210calculates each limit by the following Expression 7 to Expression 9using an output latency limit 253 received from outside and a frame rate256 obtained by performing variable-length decoding on the bitstream251, and determines whether the encoding configuration is not greaterthan the calculated limit.Layer count=int(log₂(output latency limit [s]×frame rate[fps]))+1  Expression 7Display latency picture count [TId]=int(log₂(output latency limit[s]×frame rate [fps]/2^((n-TId))))  Expression 8Continuous B-picture count [TId]=int(output latency limit [s]×frame rate[fps]/2^((n-TId))−1)  Expression 9

When the encoding configuration is greater than the limit (Yes in S203),the encoding configuration checking unit 210 shows an error indicationto that effect (S204), and the decoding process ends.

Next, the variable-length decoding unit 201 decodes predictioninformation 255 indicating a prediction mode in the bitstream 251(S205). When the prediction mode is intra prediction (Yes in S206), theintra prediction block generation unit 205 generates a prediction block261 by intra prediction (S207). When the prediction mode is interprediction (No in S206), the inter prediction block generation unit 206generates a prediction block 261 by inter prediction (S208).

Next, the variable-length decoding unit 201 decodes a transformcoefficient 254 in the bitstream 251 (S209). Next, the inversetransform/quantization unit 202 performs inverse quantization andinverse frequency transform on the transform coefficient 254 toreconstruct a difference block 258 by (S210). Next, the adding unit 203adds the difference block 258 and the prediction block 261 to generate adecoded block 259 (S211). This decoded block 259 is stored into theframe memory 204 and is used in a prediction block generation process bythe intra prediction block generation unit 205 and the inter predictionblock generation unit 206.

The video decoding apparatus 200 proceeds to a next encoding block(S212) and repeats Steps S205 to S212 until processing of all theencoding blocks within the picture is completed (S213).

Note that the processing in Steps S205 to S212 is performed on only apicture having TemporalId not larger than HighestTId 252 received fromoutside.

Next, the picture reordering unit 209 reorders decoded picturesaccording to the encoding configuration 262 having HighestTId 252 layersreceived from outside, and outputs the reordered decoded pictures asoutput video 263 (S214).

The video decoding apparatus 200 then repeats Steps S205 to S214 untilprocessing of all the pictures is completed (S215).

<Effects>

As described above, the video decoding apparatus 200 according to thepresent embodiment can decode the bitstream generated by efficientencoding. Furthermore, the video decoding apparatus 200 can check if theencoding configuration complies with the rule for practice, and when theencoding configuration does not comply with the rule, stop the decodingprocess and show an error indication.

The video decoding apparatus 200 is controlled to decode, according toHighestTId 252 received from outside, only a picture in a layer havingHighestTId 252 or less in the above description, but this is not theonly example. The video decoding apparatus 200 may always decodepictures in all layers. Alternatively, the video decoding apparatus 200may always decode, using a fixed value predetermined as HighestTId 252,only a picture in a layer not higher than a predetermined layer havingHighestTId 252.

Although the video decoding apparatus 200 checks whether or not theencoding configuration 262 complies with the rule for practice in theabove description, this function is not essential; the encodingconfiguration 262 does not need to be checked.

Although the video decoding apparatus 200 uses the output latency limit253 received from outside in the above description, a fixed valuepredetermined as the output latency limit 253 may be used.

Other features are the same as those in Embodiment 1 and therefore areomitted.

Note that the sequence in each flow is not limited to that describedabove as with the encoding side.

As described above in Embodiment 1 and Embodiment 2, the video encodingapparatus 100 according to Embodiment 1 is a video encoding apparatusthat performs scalable encoding on the input video 153 to generate thebitstream 155 (the bitstream), and performs the processing illustratedin FIG. 15.

First, the video encoding apparatus 100 determines the layer count 161of the scalable encoding so that the layer count 161 is not greater thana maximum layer count predetermined according to the frame rate (S301).The maximum layer count herein is the layer count represented in FIG.10; for example, the maximum layer count is two with a frame rate of 24fps, three with a frame rate of 30 fps, four with a frame rate of 60fps, and five with a frame rate of 120 fps. In other words, the maximumlayer count is more than or equal to four when the frame rate is morethan or equal to 60 fps. The maximum layer count is less than or equalto four when the frame rate is less than or equal to 60 fps. The maximumlayer count is more than three when the frame rate is greater than 30fps.

Furthermore, the video encoding apparatus 100 determines picture typesof the input video 153 so that the display latency picture count 164 isnot more than a maximum picture count predetermined according to theframe rate. The display latency picture count 164 herein is the numberof pictures counted during a decoding process performed by a videodecoding apparatus to decode the bitstream 155 generated by the videoencoding apparatus 100, that is, from when the video decoding apparatusstarts decoding a picture and to when the video decoding apparatusoutputs (decodes) the picture. The picture types include I-picture,P-picture, and B-picture. The maximum picture count herein is thedisplay latency picture count represented in FIG. 10; for example, themaximum picture count is one with a frame rate of 24 fps, two with aframe rate of 30 fps, three with a frame rate of 60 fps, and four with aframe rate of 120 fps. In other words, the maximum picture count is morethan or equal to three when the frame rate is more than or equal to 60fps. The maximum picture count is less than or equal to three when theframe rate is less than or equal to 60 fps. The maximum picture count ismore than two when the frame rate is more than 30 fps.

Furthermore, the video encoding apparatus 100 determines picture typesof the input video 153 so that the continuous B-picture count 162 whichis the number of continuous B-pictures is not more than a maximumcontinuous count predetermined according to the frame rate. The maximumcontinuous count herein is the continuous B-picture count represented inFIG. 10; for example, the maximum continuous count is two with a framerate of 24 fps, three with a frame rate of 30 fps, seven with a framerate of 60 fps, and 15 with a frame rate of 120 fps. In other words, themaximum continuous count is more than or equal to seven when the framerate is more than or equal to 60 fps. The maximum continuous count isless than or equal to seven when the frame rate is less than or equal to60 fps. The maximum continuous count is more than three when the framerate is greater than 30 fps.

The video encoding apparatus 100 may determine the maximum layer count,the maximum picture count, and the continuous B-picture count accordingto the frame rate as illustrated in FIG. 10. Specifically, the videoencoding apparatus 100 may set the maximum layer count, the maximumpicture count, and the continuous B-picture count to larger values witha higher frame rate.

As described above, the layer count 161, the display latency picturecount 164, and the continuous B-picture count 162 are calculated by theabove Expression 1, Expression 3, and Expression 4 using the frame rate151 and the output latency limit 152. Specifically, the maximum picturecount, an encoder output latency (output latency) from when the inputvideo 153 is input to the video encoding apparatus 100 to when thebitstream 155 is output, and the frame rate are defined by the followingrelationship.

Maximum picture count=int(log₂(encoder output latency [s]×frame rate[fps]))

The maximum continuous count, the encoder output latency, and the framerate are defined by the following relationship.Maximum continuous count=int(encoder output latency [s]×frame rate[fps]−1)

The maximum layer count, the encoder output latency, and the frame rateare defined by the following relationship.Maximum layer count=int(log₂(encoder output latency [s]×frame rate[fps]))+1

The maximum picture count [i] in each layer, the encoder output latency,and the frame rate are defined by the following relationship.Maximum picture count [i]=int(log₂(encoder output latency [s]×frame rate[fps]/2^((n-i))))

The maximum continuous count [i] in each layer, the encoder outputlatency, and the frame rate are defined by the following relationship.Maximum continuous count [i]=int(encoder output latency [s]×frame rate[fps]/2^((n-i))−1)

Here, i is an integer less than or equal to the maximum layer count andrepresents a layer, and n represents (the maximum layer count−1).

Next, using the determined layer count 161 and picture types, the videoencoding apparatus 100 performs scalable encoding on the input video 153to generate the bitstream 155 (S302). The video encoding apparatus 100encodes first information (sps_max_sub_layers_minus1), secondinformation (sps_max_num_reorder_pics), and third information(sps_max_latency_increase_plus1) indicating the determined layer count161, display latency picture count 164, and continuous B-picture count162.

The video decoding apparatus 200 according to Embodiment 2 is a videodecoding apparatus that decodes the bitstream 251 (the bitstream)obtained by performing scalable encoding on video, to generate theoutput video 263, and performs the processing illustrated in FIG. 16.

First, the video decoding apparatus 200 decodes video in the bitstream251 (S401).

Next, the video decoding apparatus 200 decodes the first information(sps_max_sub_layers_minus1) in the bitstream 251 that indicates thenumber of layers of the scalable encoding (S402). For example, thisnumber of layers is not greater than the maximum layer countpredetermined according to the frame rate of the bitstream 251.

Furthermore, the video decoding apparatus 200 decodes the secondinformation (sps_max_num_reorder_pics) in the bitstream 251 thatindicates the display latency picture count. Moreover, the videodecoding apparatus 200 decodes the third information(sps_max_latency_increase_plus1) in the bitstream 251 that indicates thecontinuous B-picture count.

Next, the video decoding apparatus 200 reorders and outputs picturesincluded in the decoded video using the number of layers indicated inthe first information, the display latency picture count indicated inthe second information, and the continuous B-picture count indicated inthe third information (S403).

Note that a specific example and a limit of the maximum layer countwhich is a maximum value of the number of layers, the maximum picturecount which is a maximum value of the display latency picture count, andthe maximum continuous count which is a maximum value of the continuousB-picture count are the same as those in the video encoding apparatus100. The relationships between (i) the maximum layer count, the maximumpicture count, and the maximum continuous count, and (ii) the frame rateand the encoder output latency are the same as those in the videoencoding apparatus 100.

The herein disclosed subject matter is to be considered descriptive andillustrative only, and the appended Claims are of a scope intended tocover and encompass not only the particular embodiments disclosed, butalso equivalent structures, methods, and/or uses.

Moreover, the processing units included in the video decoding apparatusand the video encoding apparatus according to the above embodiments aretypically implemented as an LSI which is an integrated circuit. Theseprocessing units may be individually configured as single chips or maybe configured so that a part or all of the processing units are includedin a single ship.

Furthermore, the method of circuit integration is not limited to LSIs,and implementation through a dedicated circuit or a general purposeprocessor is also possible. A Field Programmable Gate Array (FPGA) whichallows programming after LSI manufacturing or a reconfigurable processorwhich allows reconfiguration of the connections and settings of thecircuit cells inside the LSI may also be used.

Each of the structural elements in each of the above-describedembodiments may be configured in the form of an exclusive hardwareproduct, or may be realized by executing a software program suitable forthe structural element. Each of the structural elements may be realizedby means of a program executing unit, such as a CPU or a processor,reading and executing the software program recorded on a recordingmedium such as a hard disk or a semiconductor memory.

In other words, each of the video decoding apparatus and the videoencoding apparatus includes processing circuitry and storageelectrically connected to the processing circuitry (accessible from theprocessing circuitry). The processing circuitry includes at least one ofthe dedicated hardware and the program executing unit. In addition, whenthe processing circuitry includes the program executing unit, thestorage stores a software program executed by the program executingunit. Using the storage, the processing circuitry performs the videodecoding method or the video encoding method according to the aboveembodiment.

Moreover, each of the structural elements in each of the above-describedembodiments may be realized by executing the software program, or anon-transitory computer-readable recording medium on which the programis recorded. Furthermore, it goes without saying that the program can bedistributed via a transmission medium such as the Internet.

Moreover, all numerical figures used in the foregoing description aremerely exemplified for describing the exemplary embodiments in specificterms, and thus the scope of the appended Claims and their equivalentsare not limited to the exemplified numerical figures.

Furthermore, the separation of the functional blocks in the blockdiagrams is merely an example, and plural functional blocks may beimplemented as a single functional block, a single functional block maybe separated into plural functional blocks, or part of functions of afunctional block may be transferred to another functional block. Inaddition, the functions of functional blocks having similar functionsmay be processed, in parallel or by time-sharing, by single hardware orsoftware.

Moreover, the sequence in which the steps included in the video decodingmethod and the video encoding method are executed is given as an exampleto describe the exemplary embodiments in specific terms, and thus othersequences are possible. Furthermore, part of the steps may be executedsimultaneously (in parallel) with another step.

The processing described in the above embodiments may be concentratedprocessing using a single device (system) or may be distributedprocessing using more than one device. The above program may be executedby one computer or more than one computer. In other words, theconcentrated processing may be performed, or the distributed processingmay be performed.

The exemplary embodiments disclosed herein are effective particularlyin, for example, a broadcast for many end users with receiving terminalshaving various functions. For example, a signal having theabove-described data structure is broadcast. A 4k2k television or thelike terminal is capable of decomposing full-layer data. A smartphone iscapable of decomposing up to two-layer data. A transmitting apparatus iscapable of transmitting data only in a high-order layer rather than datain all the layers depending on the band congestion situation. Thisenables flexible broadcast and communication.

The herein disclosed subject matter is to be considered descriptive andillustrative only, and the appended Claims are of a scope intended tocover and encompass not only the particular embodiments disclosed, butalso equivalent structures, methods, and/or uses.

Embodiment 3

The processing described in each of embodiments can be simplyimplemented in an independent computer system, by recording, in arecording medium, one or more programs for implementing theconfigurations of the moving picture encoding method (video encodingmethod) and the moving picture decoding method (video decoding method)described in each of embodiments. The recording media may be anyrecording media as long as the program can be recorded, such as amagnetic disk, an optical disk, a magnetic optical disk, an IC card, anda semiconductor memory.

Hereinafter, the applications to the moving picture encoding method(video encoding method) and the moving picture decoding method (videodecoding method) described in each of embodiments and systems usingthereof will be described. The system has a feature of having a videocoding apparatus that includes a video encoding apparatus using thevideo encoding method and a video decoding apparatus using the videodecoding method. Other configurations in the system can be changed asappropriate depending on the cases.

FIG. 17 illustrates an overall configuration of a content providingsystem ex100 for implementing content distribution services. The areafor providing communication services is divided into cells of desiredsize, and base stations ex106, ex107, ex108, ex109, and ex110 which arefixed wireless stations are placed in each of the cells.

The content providing system ex100 is connected to devices, such as acomputer ex111, a personal digital assistant (PDA) ex112, a cameraex113, a cellular phone ex114 and a game machine ex115, via the Internetex101, an Internet service provider ex102, a telephone network ex104, aswell as the base stations ex106 to ex110, respectively.

However, the configuration of the content providing system ex100 is notlimited to the configuration shown in FIG. 17, and a combination inwhich any of the elements are connected is acceptable. In addition, eachdevice may be directly connected to the telephone network ex104, ratherthan via the base stations ex106 to ex110 which are the fixed wirelessstations. Furthermore, the devices may be interconnected to each othervia a short distance wireless communication and others.

The camera ex113, such as a digital video camera, is capable ofcapturing video. A camera ex116, such as a digital camera, is capable ofcapturing both still images and video. Furthermore, the cellular phoneex114 may be the one that meets any of the standards such as GlobalSystem for Mobile Communications (GSM) (registered trademark), CodeDivision Multiple Access (CDMA), Wideband-Code Division Multiple Access(W-CDMA), Long Term Evolution (LTE), and High Speed Packet Access(HSPA). Alternatively, the cellular phone ex114 may be a PersonalHandyphone System (PHS).

In the content providing system ex100, a streaming server ex103 isconnected to the camera ex113 and others via the telephone network ex104and the base station ex109, which enables distribution of images of alive show and others. In such a distribution, a content (for example,video of a music live show) captured by the user using the camera ex113is encoded as described above in each of embodiments (i.e., the camerafunctions as the video encoding apparatus according to an aspect of thepresent disclosure), and the encoded content is transmitted to thestreaming server ex103. On the other hand, the streaming server ex103carries out stream distribution of the transmitted content data to theclients upon their requests. The clients include the computer ex111, thePDA ex112, the camera ex113, the cellular phone ex114, and the gamemachine ex115 that are capable of decoding the above-mentioned encodeddata. Each of the devices that have received the distributed datadecodes and reproduces the encoded data (i.e., functions as the videodecoding apparatus according to an aspect of the present disclosure).

The captured data may be encoded by the camera ex113 or the streamingserver ex103 that transmits the data, or the encoding processes may beshared between the camera ex113 and the streaming server ex103.Similarly, the distributed data may be decoded by the clients or thestreaming server ex103, or the decoding processes may be shared betweenthe clients and the streaming server ex103. Furthermore, the data of thestill images and video captured by not only the camera ex113 but alsothe camera ex116 may be transmitted to the streaming server ex103through the computer ex111. The encoding processes may be performed bythe camera ex116, the computer ex111, or the streaming server ex103, orshared among them.

Furthermore, the coding processes may be performed by an LSI ex500generally included in each of the computer ex111 and the devices. TheLSI ex500 may be configured of a single chip or a plurality of chips.Software for coding video may be integrated into some type of arecording medium (such as a CD-ROM, a flexible disk, and a hard disk)that is readable by the computer ex111 and others, and the codingprocesses may be performed using the software. Furthermore, when thecellular phone ex114 is equipped with a camera, the video data obtainedby the camera may be transmitted. The video data is data encoded by theLSI ex500 included in the cellular phone ex114.

Furthermore, the streaming server ex103 may be composed of servers andcomputers, and may decentralize data and process the decentralized data,record, or distribute data.

As described above, the clients may receive and reproduce the encodeddata in the content providing system ex100. In other words, the clientscan receive and decode information transmitted by the user, andreproduce the decoded data in real time in the content providing systemex100, so that the user who does not have any particular right andequipment can implement personal broadcasting.

Aside from the example of the content providing system ex100, at leastone of the moving picture coding apparatus (video coding apparatus)described in each of embodiments may be implemented in a digitalbroadcasting system ex200 illustrated in FIG. 18. More specifically, abroadcast station ex201 communicates or transmits, via radio waves to abroadcast satellite ex202, multiplexed data obtained by multiplexingaudio data and others onto video data. The video data is data encoded bythe moving picture encoding method described in each of embodiments(i.e., data encoded by the video encoding apparatus according to anaspect of the present disclosure). Upon receipt of the multiplexed data,the broadcast satellite ex202 transmits radio waves for broadcasting.Then, a home-use antenna ex204 with a satellite broadcast receptionfunction receives the radio waves. Next, a device such as a television(receiver) ex300 and a set top box (STB) ex217 decodes the receivedmultiplexed data, and reproduces the decoded data (i.e., functions asthe video decoding apparatus according to an aspect of the presentdisclosure).

Furthermore, a reader/recorder ex218 (i) reads and decodes themultiplexed data recorded on a recording medium ex215, such as a DVD anda BD, or (i) encodes video signals in the recording medium ex215, and insome cases, writes data obtained by multiplexing an audio signal on theencoded data. The reader/recorder ex218 can include the moving picturedecoding apparatus or the moving picture encoding apparatus as shown ineach of embodiments. In this case, the reproduced video signals aredisplayed on the monitor ex219, and can be reproduced by another deviceor system using the recording medium ex215 on which the multiplexed datais recorded. It is also possible to implement the moving picturedecoding apparatus in the set top box ex217 connected to the cable ex203for a cable television or to the antenna ex204 for satellite and/orterrestrial broadcasting, so as to display the video signals on themonitor ex219 of the television ex300. The moving picture decodingapparatus may be implemented not in the set top box but in thetelevision ex300.

FIG. 19 illustrates the television (receiver) ex300 that uses the movingpicture encoding method and the moving picture decoding method describedin each of embodiments. The television ex300 includes: a tuner ex301that obtains or provides multiplexed data obtained by multiplexing audiodata onto video data, through the antenna ex204 or the cable ex203, etc.that receives a broadcast; a modulation/demodulation unit ex302 thatdemodulates the received multiplexed data or modulates data intomultiplexed data to be supplied outside; and amultiplexing/demultiplexing unit ex303 that demultiplexes the modulatedmultiplexed data into video data and audio data, or multiplexes videodata and audio data encoded by a signal processing unit ex306 into data.

The television ex300 further includes: a signal processing unit ex306including an audio signal processing unit ex304 and a video signalprocessing unit ex305 that code each of audio data and video data,(which function as the video coding apparatus according to the aspectsof the present disclosure); and an output unit ex309 including a speakerex307 that provides the decoded audio signal, and a display unit ex308that displays the decoded video signal, such as a display. Furthermore,the television ex300 includes an interface unit ex317 including anoperation input unit ex312 that receives an input of a user operation.Furthermore, the television ex300 includes a control unit ex310 thatcontrols overall each constituent element of the television ex300, and apower supply circuit unit ex311 that supplies power to each of theelements. Other than the operation input unit ex312, the interface unitex317 may include: a bridge ex313 that is connected to an externaldevice, such as the reader/recorder ex218; a slot unit ex314 forenabling attachment of the recording medium ex216, such as an SD card; adriver ex315 to be connected to an external recording medium, such as ahard disk; and a modem ex316 to be connected to a telephone network.Here, the recording medium ex216 can electrically record informationusing a non-volatile/volatile semiconductor memory element for storage.The constituent elements of the television ex300 are connected to eachother through a synchronous bus.

First, the configuration in which the television ex300 decodesmultiplexed data obtained from outside through the antenna ex204 andothers and reproduces the decoded data will be described. In thetelevision ex300, upon a user operation through a remote controllerex220 and others, the multiplexing/demultiplexing unit ex303demultiplexes the multiplexed data demodulated by themodulation/demodulation unit ex302, under control of the control unitex310 including a CPU. Furthermore, the audio signal processing unitex304 decodes the demultiplexed audio data, and the video signalprocessing unit ex305 decodes the demultiplexed video data, using thedecoding method described in each of embodiments, in the televisionex300. The output unit ex309 provides the decoded video signal and audiosignal outside, respectively. When the output unit ex309 provides thevideo signal and the audio signal, the signals may be temporarily storedin buffers ex318 and ex319, and others so that the signals arereproduced in synchronization with each other. Furthermore, thetelevision ex300 may read multiplexed data not through a broadcast andothers but from the recording media ex215 and ex216, such as a magneticdisk, an optical disk, and a SD card. Next, a configuration in which thetelevision ex300 encodes an audio signal and a video signal, andtransmits the data outside or writes the data on a recording medium willbe described. In the television ex300, upon a user operation through theremote controller ex220 and others, the audio signal processing unitex304 encodes an audio signal, and the video signal processing unitex305 encodes a video signal, under control of the control unit ex310using the encoding method described in each of embodiments. Themultiplexing/demultiplexing unit ex303 multiplexes the encoded videosignal and audio signal, and provides the resulting signal outside. Whenthe multiplexing/demultiplexing unit ex303 multiplexes the video signaland the audio signal, the signals may be temporarily stored in thebuffers ex320 and ex321, and others so that the signals are reproducedin synchronization with each other. Here, the buffers ex318, ex319,ex320, and ex321 may be plural as illustrated, or at least one buffermay be shared in the television ex300. Furthermore, data may be storedin a buffer so that the system overflow and underflow may be avoidedbetween the modulation/demodulation unit ex302 and themultiplexing/demultiplexing unit ex303, for example.

Furthermore, the television ex300 may include a configuration forreceiving an AV input from a microphone or a camera other than theconfiguration for obtaining audio and video data from a broadcast or arecording medium, and may encode the obtained data. Although thetelevision ex300 can encode, multiplex, and provide outside data in thedescription, it may be capable of only receiving, decoding, andproviding outside data but not the encoding, multiplexing, and providingoutside data.

Furthermore, when the reader/recorder ex218 reads or writes multiplexeddata from or on a recording medium, one of the television ex300 and thereader/recorder ex218 may code the multiplexed data, and the televisionex300 and the reader/recorder ex218 may share the coding partly.

As an example, FIG. 20 illustrates a configuration of an informationreproducing/recording unit ex400 when data is read or written from or onan optical disk. The information reproducing/recording unit ex400includes constituent elements ex401, ex402, ex403, ex404, ex405, ex406,and ex407 to be described hereinafter. The optical head ex401 irradiatesa laser spot in a recording surface of the recording medium ex215 thatis an optical disk to write information, and detects reflected lightfrom the recording surface of the recording medium ex215 to read theinformation. The modulation recording unit ex402 electrically drives asemiconductor laser included in the optical head ex401, and modulatesthe laser light according to recorded data. The reproductiondemodulating unit ex403 amplifies a reproduction signal obtained byelectrically detecting the reflected light from the recording surfaceusing a photo detector included in the optical head ex401, anddemodulates the reproduction signal by separating a signal componentrecorded on the recording medium ex215 to reproduce the necessaryinformation. The buffer ex404 temporarily holds the information to berecorded on the recording medium ex215 and the information reproducedfrom the recording medium ex215. The disk motor ex405 rotates therecording medium ex215. The servo control unit ex406 moves the opticalhead ex401 to a predetermined information track while controlling therotation drive of the disk motor ex405 so as to follow the laser spot.The system control unit ex407 controls overall the informationreproducing/recording unit ex400. The reading and writing processes canbe implemented by the system control unit ex407 using variousinformation stored in the buffer ex404 and generating and adding newinformation as necessary, and by the modulation recording unit ex402,the reproduction demodulating unit ex403, and the servo control unitex406 that record and reproduce information through the optical headex401 while being operated in a coordinated manner. The system controlunit ex407 includes, for example, a microprocessor, and executesprocessing by causing a computer to execute a program for read andwrite.

Although the optical head ex401 irradiates a laser spot in thedescription, it may perform high-density recording using near fieldlight.

FIG. 21 illustrates the recording medium ex215 that is the optical disk.On the recording surface of the recording medium ex215, guide groovesare spirally formed, and an information track ex230 records, in advance,address information indicating an absolute position on the diskaccording to change in a shape of the guide grooves. The addressinformation includes information for determining positions of recordingblocks ex231 that are a unit for recording data. Reproducing theinformation track ex230 and reading the address information in anapparatus that records and reproduces data can lead to determination ofthe positions of the recording blocks. Furthermore, the recording mediumex215 includes a data recording area ex233, an inner circumference areaex232, and an outer circumference area ex234. The data recording areaex233 is an area for use in recording the user data. The innercircumference area ex232 and the outer circumference area ex234 that areinside and outside of the data recording area ex233, respectively arefor specific use except for recording the user data. The informationreproducing/recording unit 400 reads and writes encoded audio, encodedvideo data, or multiplexed data obtained by multiplexing the encodedaudio and video data, from and on the data recording area ex233 of therecording medium ex215.

Although an optical disk having a layer, such as a DVD and a BD isdescribed as an example in the description, the optical disk is notlimited to such, and may be an optical disk having a multilayerstructure and capable of being recorded on a part other than thesurface. Furthermore, the optical disk may have a structure formultidimensional recording/reproduction, such as recording ofinformation using light of colors with different wavelengths in the sameportion of the optical disk and for recording information havingdifferent layers from various angles.

Furthermore, a car ex210 having an antenna ex205 can receive data fromthe satellite ex202 and others, and reproduce video on a display devicesuch as a car navigation system ex211 set in the car ex210, in thedigital broadcasting system ex200. Here, a configuration of the carnavigation system ex211 will be a configuration, for example, includinga GPS receiving unit from the configuration illustrated in FIG. 19. Thesame will be true for the configuration of the computer ex111, thecellular phone ex114, and others.

FIG. 22A illustrates the cellular phone ex114 that uses the movingpicture coding method described in embodiments. The cellular phone ex114includes: an antenna ex350 for transmitting and receiving radio wavesthrough the base station ex110; a camera unit ex365 capable of capturingmoving and still images; and a display unit ex358 such as a liquidcrystal display for displaying the data such as decoded video capturedby the camera unit ex365 or received by the antenna ex350. The cellularphone ex114 further includes: a main body unit including an operationkey unit ex366; an audio output unit ex357 such as a speaker for outputof audio; an audio input unit ex356 such as a microphone for input ofaudio; a memory unit ex367 for storing captured video or still pictures,recorded audio, coded data of the received video, the still pictures,e-mails, or others; and a slot unit ex364 that is an interface unit fora recording medium that stores data in the same manner as the memoryunit ex367.

Next, an example of a configuration of the cellular phone ex114 will bedescribed with reference to FIG. 22B. In the cellular phone ex114, amain control unit ex360 designed to control overall each unit of themain body including the display unit ex358 as well as the operation keyunit ex366 is connected mutually, via a synchronous bus ex370, to apower supply circuit unit ex361, an operation input control unit ex362,a video signal processing unit ex355, a camera interface unit ex363, aliquid crystal display (LCD) control unit ex359, amodulation/demodulation unit ex352, a multiplexing/demultiplexing unitex353, an audio signal processing unit ex354, the slot unit ex364, andthe memory unit ex367.

When a call-end key or a power key is turned ON by a user's operation,the power supply circuit unit ex361 supplies the respective units withpower from a battery pack so as to activate the cell phone ex114.

In the cellular phone ex114, the audio signal processing unit ex354converts the audio signals collected by the audio input unit ex356 invoice conversation mode into digital audio signals under the control ofthe main control unit ex360 including a CPU, ROM, and RAM. Then, themodulation/demodulation unit ex352 performs spread spectrum processingon the digital audio signals, and the transmitting and receiving unitex351 performs digital-to-analog conversion and frequency conversion onthe data, so as to transmit the resulting data via the antenna ex350.Also, in the cellular phone ex114, the transmitting and receiving unitex351 amplifies the data received by the antenna ex350 in voiceconversation mode and performs frequency conversion and theanalog-to-digital conversion on the data. Then, themodulation/demodulation unit ex352 performs inverse spread spectrumprocessing on the data, and the audio signal processing unit ex354converts it into analog audio signals, so as to output them via theaudio output unit ex357.

Furthermore, when an e-mail in data communication mode is transmitted,text data of the e-mail inputted by operating the operation key unitex366 and others of the main body is sent out to the main control unitex360 via the operation input control unit ex362. The main control unitex360 causes the modulation/demodulation unit ex352 to perform spreadspectrum processing on the text data, and the transmitting and receivingunit ex351 performs the digital-to-analog conversion and the frequencyconversion on the resulting data to transmit the data to the basestation ex110 via the antenna ex350. When an e-mail is received,processing that is approximately inverse to the processing fortransmitting an e-mail is performed on the received data, and theresulting data is provided to the display unit ex358.

When video, still images, or video and audio in data communication modeis or are transmitted, the video signal processing unit ex355 compressesand encodes video signals supplied from the camera unit ex365 using themoving picture encoding method shown in each of embodiments (i.e.,functions as the video encoding apparatus according to the aspect of thepresent disclosure), and transmits the encoded video data to themultiplexing/demultiplexing unit ex353. In contrast, during when thecamera unit ex365 captures video, still images, and others, the audiosignal processing unit ex354 encodes audio signals collected by theaudio input unit ex356, and transmits the encoded audio data to themultiplexing/demultiplexing unit ex353.

The multiplexing/demultiplexing unit ex353 multiplexes the encoded videodata supplied from the video signal processing unit ex355 and theencoded audio data supplied from the audio signal processing unit ex354,using a predetermined method. Then, the modulation/demodulation unit(modulation/demodulation circuit unit) ex352 performs spread spectrumprocessing on the multiplexed data, and the transmitting and receivingunit ex351 performs digital-to-analog conversion and frequencyconversion on the data so as to transmit the resulting data via theantenna ex350.

When receiving data of a video file which is linked to a Web page andothers in data communication mode or when receiving an e-mail with videoand/or audio attached, in order to decode the multiplexed data receivedvia the antenna ex350, the multiplexing/demultiplexing unit ex353demultiplexes the multiplexed data into a video data bit stream and anaudio data bit stream, and supplies the video signal processing unitex355 with the encoded video data and the audio signal processing unitex354 with the encoded audio data, through the synchronous bus ex370.The video signal processing unit ex355 decodes the video signal using amoving picture decoding method corresponding to the moving pictureencoding method shown in each of embodiments (i.e., functions as thevideo decoding apparatus according to the aspect of the presentdisclosure), and then the display unit ex358 displays, for instance, thevideo and still images included in the video file linked to the Web pagevia the LCD control unit ex359. Furthermore, the audio signal processingunit ex354 decodes the audio signal, and the audio output unit ex357provides the audio.

Furthermore, similarly to the television ex300, a terminal such as thecellular phone ex114 probably have 3 types of implementationconfigurations including not only (i) a transmitting and receivingterminal including both an encoding apparatus and a decoding apparatus,but also (ii) a transmitting terminal including only an encodingapparatus and (iii) a receiving terminal including only a decodingapparatus. Although the digital broadcasting system ex200 receives andtransmits the multiplexed data obtained by multiplexing audio data ontovideo data in the description, the multiplexed data may be data obtainedby multiplexing not audio data but character data related to video ontovideo data, and may be not multiplexed data but video data itself.

As such, the moving picture coding method in each of embodiments can beused in any of the devices and systems described. Thus, the advantagesdescribed in each of embodiments can be obtained.

Furthermore, various modifications and revisions can be made in any ofthe embodiments in the present disclosure.

Embodiment 4

Video data can be generated by switching, as necessary, between (i) themoving picture encoding method or the moving picture encoding apparatusshown in each of embodiments and (ii) a moving picture encoding methodor a moving picture encoding apparatus in conformity with a differentstandard, such as MPEG-2, MPEG-4 AVC, and VC-1.

Here, when a plurality of video data that conforms to the differentstandards is generated and is then decoded, the decoding methods need tobe selected to conform to the different standards. However, since towhich standard each of the plurality of the video data to be decodedconforms cannot be detected, there is a problem that an appropriatedecoding method cannot be selected.

In order to solve the problem, multiplexed data obtained by multiplexingaudio data and others onto video data has a structure includingidentification information indicating to which standard the video dataconforms. The specific structure of the multiplexed data including thevideo data generated in the moving picture encoding method and by themoving picture encoding apparatus shown in each of embodiments will behereinafter described. The multiplexed data is a digital stream in theMPEG-2 Transport Stream format.

FIG. 23 illustrates a structure of multiplexed data. As illustrated inFIG. 23, the multiplexed data can be obtained by multiplexing at leastone of a video stream, an audio stream, a presentation graphics stream(PG), and an interactive graphics stream. The video stream representsprimary video and secondary video of a movie, the audio stream (IG)represents a primary audio part and a secondary audio part to be mixedwith the primary audio part, and the presentation graphics streamrepresents subtitles of the movie. Here, the primary video is normalvideo to be displayed on a screen, and the secondary video is video tobe displayed on a smaller window in the primary video. Furthermore, theinteractive graphics stream represents an interactive screen to begenerated by arranging the GUI components on a screen. The video streamis encoded in the moving picture encoding method or by the movingpicture encoding apparatus shown in each of embodiments, or in a movingpicture encoding method or by a moving picture encoding apparatus inconformity with a conventional standard, such as MPEG-2, MPEG-4 AVC, andVC-1. The audio stream is encoded in accordance with a standard, such asDolby-AC-3, Dolby Digital Plus, MLP, DTS, DTS-HD, and linear PCM.

Each stream included in the multiplexed data is identified by PID. Forexample, 0x1011 is allocated to the video stream to be used for video ofa movie, 0x1100 to 0x111F are allocated to the audio streams, 0x1200 to0x121F are allocated to the presentation graphics streams, 0x1400 to0x141F are allocated to the interactive graphics streams, 0x1B00 to0x1B1F are allocated to the video streams to be used for secondary videoof the movie, and 0x1A00 to 0x1A1F are allocated to the audio streams tobe used for the secondary audio to be mixed with the primary audio.

FIG. 24 schematically illustrates how data is multiplexed. First, avideo stream ex235 composed of video frames and an audio stream ex238composed of audio frames are transformed into a stream of PES packetsex236 and a stream of PES packets ex239, and further into TS packetsex237 and TS packets ex240, respectively. Similarly, data of apresentation graphics stream ex241 and data of an interactive graphicsstream ex244 are transformed into a stream of PES packets ex242 and astream of PES packets ex245, and further into TS packets ex243 and TSpackets ex246, respectively. These TS packets are multiplexed into astream to obtain multiplexed data ex247.

FIG. 25 illustrates how a video stream is stored in a stream of PESpackets in more detail. The first bar in FIG. 25 shows a video framestream in a video stream. The second bar shows the stream of PESpackets. As indicated by arrows denoted as yy1, yy2, yy3, and yy4 inFIG. 25, the video stream is divided into pictures as I pictures, Bpictures, and P pictures each of which is a video presentation unit, andthe pictures are stored in a payload of each of the PES packets. Each ofthe PES packets has a PES header, and the PES header stores aPresentation Time-Stamp (PTS) indicating a display time of the picture,and a Decoding Time-Stamp (DTS) indicating a decoding time of thepicture.

FIG. 26 illustrates a format of TS packets to be finally written on themultiplexed data. Each of the TS packets is a 188-byte fixed lengthpacket including a 4-byte TS header having information, such as a PIDfor identifying a stream and a 184-byte TS payload for storing data. ThePES packets are divided, and stored in the TS payloads, respectively.When a BD ROM is used, each of the TS packets is given a 4-byteTP_Extra_Header, thus resulting in 192-byte source packets. The sourcepackets are written on the multiplexed data. The TP_Extra_Header storesinformation such as an Arrival_Time_Stamp (ATS). The ATS shows atransfer start time at which each of the TS packets is to be transferredto a PID filter. The source packets are arranged in the multiplexed dataas shown at the bottom of FIG. 26. The numbers incrementing from thehead of the multiplexed data are called source packet numbers (SPNs).

Each of the TS packets included in the multiplexed data includes notonly streams of audio, video, subtitles and others, but also a ProgramAssociation Table (PAT), a Program Map Table (PMT), and a Program ClockReference (PCR). The PAT shows what a PID in a PMT used in themultiplexed data indicates, and a PID of the PAT itself is registered aszero. The PMT stores PIDs of the streams of video, audio, subtitles andothers included in the multiplexed data, and attribute information ofthe streams corresponding to the PIDs. The PMT also has variousdescriptors relating to the multiplexed data. The descriptors haveinformation such as copy control information showing whether copying ofthe multiplexed data is permitted or not. The PCR stores STC timeinformation corresponding to an ATS showing when the PCR packet istransferred to a decoder, in order to achieve synchronization between anArrival Time Clock (ATC) that is a time axis of ATSs, and an System TimeClock (STC) that is a time axis of PTSs and DTSs.

FIG. 27 illustrates the data structure of the PMT in detail. A PMTheader is disposed at the top of the PMT. The PMT header describes thelength of data included in the PMT and others. A plurality ofdescriptors relating to the multiplexed data is disposed after the PMTheader. Information such as the copy control information is described inthe descriptors. After the descriptors, a plurality of pieces of streaminformation relating to the streams included in the multiplexed data isdisposed. Each piece of stream information includes stream descriptorseach describing information, such as a stream type for identifying acompression codec of a stream, a stream PID, and stream attributeinformation (such as a frame rate or an aspect ratio). The streamdescriptors are equal in number to the number of streams in themultiplexed data.

When the multiplexed data is recorded on a recording medium and others,it is recorded together with multiplexed data information files.

Each of the multiplexed data information files is management informationof the multiplexed data as shown in FIG. 28. The multiplexed datainformation files are in one to one correspondence with the multiplexeddata, and each of the files includes multiplexed data information,stream attribute information, and an entry map.

As illustrated in FIG. 28, the multiplexed data information includes asystem rate, a reproduction start time, and a reproduction end time. Thesystem rate indicates the maximum transfer rate at which a system targetdecoder to be described later transfers the multiplexed data to a PIDfilter. The intervals of the ATSs included in the multiplexed data areset to not higher than a system rate. The reproduction start timeindicates a PTS in a video frame at the head of the multiplexed data. Aninterval of one frame is added to a PTS in a video frame at the end ofthe multiplexed data, and the PTS is set to the reproduction end time.

As shown in FIG. 29, a piece of attribute information is registered inthe stream attribute information, for each PID of each stream includedin the multiplexed data. Each piece of attribute information hasdifferent information depending on whether the corresponding stream is avideo stream, an audio stream, a presentation graphics stream, or aninteractive graphics stream. Each piece of video stream attributeinformation carries information including what kind of compression codecis used for compressing the video stream, and the resolution, aspectratio and frame rate of the pieces of picture data that is included inthe video stream. Each piece of audio stream attribute informationcarries information including what kind of compression codec is used forcompressing the audio stream, how many channels are included in theaudio stream, which language the audio stream supports, and how high thesampling frequency is. The video stream attribute information and theaudio stream attribute information are used for initialization of adecoder before the player plays back the information.

In the present embodiment, the multiplexed data to be used is of astream type included in the PMT. Furthermore, when the multiplexed datais recorded on a recording medium, the video stream attributeinformation included in the multiplexed data information is used. Morespecifically, the moving picture encoding method or the moving pictureencoding apparatus described in each of embodiments includes a step or aunit for allocating unique information indicating video data generatedby the moving picture encoding method or the moving picture encodingapparatus in each of embodiments, to the stream type included in the PMTor the video stream attribute information. With the configuration, thevideo data generated by the moving picture encoding method or the movingpicture encoding apparatus described in each of embodiments can bedistinguished from video data that conforms to another standard.

Furthermore, FIG. 30 illustrates steps of the moving picture decodingmethod according to the present embodiment. In Step exS100, the streamtype included in the PMT or the video stream attribute informationincluded in the multiplexed data information is obtained from themultiplexed data. Next, in Step exS101, it is determined whether or notthe stream type or the video stream attribute information indicates thatthe multiplexed data is generated by the moving picture encoding methodor the moving picture encoding apparatus in each of embodiments. When itis determined that the stream type or the video stream attributeinformation indicates that the multiplexed data is generated by themoving picture encoding method or the moving picture encoding apparatusin each of embodiments, in Step exS102, decoding is performed by themoving picture decoding method in each of embodiments. Furthermore, whenthe stream type or the video stream attribute information indicatesconformance to the conventional standards, such as MPEG-2, MPEG-4 AVC,and VC-1, in Step exS103, decoding is performed by a moving picturedecoding method in conformity with the conventional standards.

As such, allocating a new unique value to the stream type or the videostream attribute information enables determination whether or not themoving picture decoding method or the moving picture decoding apparatusthat is described in each of embodiments can perform decoding. Even whenmultiplexed data that conforms to a different standard is input, anappropriate decoding method or apparatus can be selected. Thus, itbecomes possible to decode information without any error. Furthermore,the moving picture encoding method or apparatus, or the moving picturedecoding method or apparatus in the present embodiment can be used inthe devices and systems described above.

Embodiment 5

Each of the moving picture coding method and the moving picture codingapparatus in each of embodiments is typically achieved in the form of anintegrated circuit or a Large Scale Integrated (LSI) circuit. As anexample of the LSI, FIG. 31 illustrates a configuration of the LSI ex500that is made into one chip. The LSI ex500 includes elements ex501,ex502, ex503, ex504, ex505, ex506, ex507, ex508, and ex509 to bedescribed below, and the elements are connected to each other through abus ex510. The power supply circuit unit ex505 is activated by supplyingeach of the elements with power when the power supply circuit unit ex505is turned on.

For example, when encoding is performed, the LSI ex500 receives an AVsignal from a microphone ex117, a camera ex113, and others through an AVIO ex509 under control of a control unit ex501 including a CPU ex502, amemory controller ex503, a stream controller ex504, and a drivingfrequency control unit ex512. The received AV signal is temporarilystored in an external memory ex511, such as an SDRAM. Under control ofthe control unit ex501, the stored data is segmented into data portionsaccording to the processing amount and speed to be transmitted to asignal processing unit ex507. Then, the signal processing unit ex507encodes an audio signal and/or a video signal. Here, the encoding of thevideo signal is the encoding described in each of embodiments.Furthermore, the signal processing unit ex507 sometimes multiplexes theencoded audio data and the encoded video data, and a stream IO ex506provides the multiplexed data outside. The provided multiplexed data istransmitted to the base station ex107, or written on the recordingmedium ex215. When data sets are multiplexed, the data should betemporarily stored in the buffer ex508 so that the data sets aresynchronized with each other.

Although the memory ex511 is an element outside the LSI ex500, it may beincluded in the LSI ex500. The buffer ex508 is not limited to onebuffer, but may be composed of buffers. Furthermore, the LSI ex500 maybe made into one chip or a plurality of chips.

Furthermore, although the control unit ex501 includes the CPU ex502, thememory controller ex503, the stream controller ex504, the drivingfrequency control unit ex512, the configuration of the control unitex501 is not limited to such. For example, the signal processing unitex507 may further include a CPU. Inclusion of another CPU in the signalprocessing unit ex507 can improve the processing speed. Furthermore, asanother example, the CPU ex502 may serve as or be a part of the signalprocessing unit ex507, and, for example, may include an audio signalprocessing unit. In such a case, the control unit ex501 includes thesignal processing unit ex507 or the CPU ex502 including a part of thesignal processing unit ex507.

The name used here is LSI, but it may also be called IC, system LSI,super LSI, or ultra LSI depending on the degree of integration.

Moreover, ways to achieve integration are not limited to the LSI, and aspecial circuit or a general purpose processor and so forth can alsoachieve the integration. Field Programmable Gate Array (FPGA) that canbe programmed after manufacturing LSIs or a reconfigurable processorthat allows re-configuration of the connection or configuration of anLSI can be used for the same purpose. Such a programmable logic devicecan typically execute the moving picture coding method according to anyof the above embodiments, by loading or reading from a memory or thelike one or more programs that are included in software or firmware.

In the future, with advancement in semiconductor technology, a brand-newtechnology may replace LSI. The functional blocks can be integratedusing such a technology. The possibility is that the present disclosureis applied to biotechnology.

Embodiment 6

When video data generated in the moving picture encoding method or bythe moving picture encoding apparatus described in each of embodimentsis decoded, compared to when video data that conforms to a conventionalstandard, such as MPEG-2, MPEG-4 AVC, and VC-1 is decoded, theprocessing amount probably increases. Thus, the LSI ex500 needs to beset to a driving frequency higher than that of the CPU ex502 to be usedwhen video data in conformity with the conventional standard is decoded.However, there is a problem that the power consumption increases whenthe driving frequency is set higher.

In order to solve the problem, the moving picture decoding apparatus,such as the television ex300 and the LSI ex500 is configured todetermine to which standard the video data conforms, and switch betweenthe driving frequencies according to the determined standard. FIG. 32illustrates a configuration ex800 in the present embodiment. A drivingfrequency switching unit ex803 sets a driving frequency to a higherdriving frequency when video data is generated by the moving pictureencoding method or the moving picture encoding apparatus described ineach of embodiments. Then, the driving frequency switching unit ex803instructs a decoding processing unit ex801 that executes the movingpicture decoding method described in each of embodiments to decode thevideo data. When the video data conforms to the conventional standard,the driving frequency switching unit ex803 sets a driving frequency to alower driving frequency than that of the video data generated by themoving picture encoding method or the moving picture encoding apparatusdescribed in each of embodiments. Then, the driving frequency switchingunit ex803 instructs the decoding processing unit ex802 that conforms tothe conventional standard to decode the video data.

More specifically, the driving frequency switching unit ex803 includesthe CPU ex502 and the driving frequency control unit ex512 in FIG. 31.Here, each of the decoding processing unit ex801 that executes themoving picture decoding method described in each of embodiments and thedecoding processing unit ex802 that conforms to the conventionalstandard corresponds to the signal processing unit ex507 in FIG. 31. TheCPU ex502 determines to which standard the video data conforms. Then,the driving frequency control unit ex512 determines a driving frequencybased on a signal from the CPU ex502. Furthermore, the signal processingunit ex507 decodes the video data based on the signal from the CPUex502. For example, the identification information described inEmbodiment 4 is probably used for identifying the video data. Theidentification information is not limited to the one described inEmbodiment 4 but may be any information as long as the informationindicates to which standard the video data conforms. For example, whenwhich standard video data conforms to can be determined based on anexternal signal for determining that the video data is used for atelevision or a disk, etc., the determination may be made based on suchan external signal. Furthermore, the CPU ex502 selects a drivingfrequency based on, for example, a look-up table in which the standardsof the video data are associated with the driving frequencies as shownin FIG. 34. The driving frequency can be selected by storing the look-uptable in the buffer ex508 and in an internal memory of an LSI, and withreference to the look-up table by the CPU ex502.

FIG. 33 illustrates steps for executing a method in the presentembodiment. First, in Step exS200, the signal processing unit ex507obtains identification information from the multiplexed data. Next, inStep exS201, the CPU ex502 determines whether or not the video data isgenerated by the encoding method and the encoding apparatus described ineach of embodiments, based on the identification information. When thevideo data is generated by the moving picture encoding method and themoving picture encoding apparatus described in each of embodiments, inStep exS202, the CPU ex502 transmits a signal for setting the drivingfrequency to a higher driving frequency to the driving frequency controlunit ex512. Then, the driving frequency control unit ex512 sets thedriving frequency to the higher driving frequency. On the other hand,when the identification information indicates that the video dataconforms to the conventional standard, such as MPEG-2, MPEG-4 AVC, andVC-1, in Step exS203, the CPU ex502 transmits a signal for setting thedriving frequency to a lower driving frequency to the driving frequencycontrol unit ex512. Then, the driving frequency control unit ex512 setsthe driving frequency to the lower driving frequency than that in thecase where the video data is generated by the moving picture encodingmethod and the moving picture encoding apparatus described in each ofembodiment.

Furthermore, along with the switching of the driving frequencies, thepower conservation effect can be improved by changing the voltage to beapplied to the LSI ex500 or an apparatus including the LSI ex500. Forexample, when the driving frequency is set lower, the voltage to beapplied to the LSI ex500 or the apparatus including the LSI ex500 isprobably set to a voltage lower than that in the case where the drivingfrequency is set higher.

Furthermore, when the processing amount for decoding is larger, thedriving frequency may be set higher, and when the processing amount fordecoding is smaller, the driving frequency may be set lower as themethod for setting the driving frequency. Thus, the setting method isnot limited to the ones described above. For example, when theprocessing amount for decoding video data in conformity with MPEG-4 AVCis larger than the processing amount for decoding video data generatedby the moving picture encoding method and the moving picture encodingapparatus described in each of embodiments, the driving frequency isprobably set in reverse order to the setting described above.

Furthermore, the method for setting the driving frequency is not limitedto the method for setting the driving frequency lower. For example, whenthe identification information indicates that the video data isgenerated by the moving picture encoding method and the moving pictureencoding apparatus described in each of embodiments, the voltage to beapplied to the LSI ex500 or the apparatus including the LSI ex500 isprobably set higher. When the identification information indicates thatthe video data conforms to the conventional standard, such as MPEG-2,MPEG-4 AVC, and VC-1, the voltage to be applied to the LSI ex500 or theapparatus including the LSI ex500 is probably set lower. As anotherexample, when the identification information indicates that the videodata is generated by the moving picture encoding method and the movingpicture encoding apparatus described in each of embodiments, the drivingof the CPU ex502 does not probably have to be suspended. When theidentification information indicates that the video data conforms to theconventional standard, such as MPEG-2, MPEG-4 AVC, and VC-1, the drivingof the CPU ex502 is probably suspended at a given time because the CPUex502 has extra processing capacity. Even when the identificationinformation indicates that the video data is generated by the movingpicture encoding method and the moving picture encoding apparatusdescribed in each of embodiments, in the case where the CPU ex502 hasextra processing capacity, the driving of the CPU ex502 is probablysuspended at a given time. In such a case, the suspending time isprobably set shorter than that in the case where when the identificationinformation indicates that the video data conforms to the conventionalstandard, such as MPEG-2, MPEG-4 AVC, and VC-1.

Accordingly, the power conservation effect can be improved by switchingbetween the driving frequencies in accordance with the standard to whichthe video data conforms. Furthermore, when the LSI ex500 or theapparatus including the LSI ex500 is driven using a battery, the batterylife can be extended with the power conservation effect.

Embodiment 7

There are cases where a plurality of video data that conforms todifferent standards, is provided to the devices and systems, such as atelevision and a cellular phone. In order to enable decoding theplurality of video data that conforms to the different standards, thesignal processing unit ex507 of the LSI ex500 needs to conform to thedifferent standards. However, the problems of increase in the scale ofthe circuit of the LSI ex500 and increase in the cost arise with theindividual use of the signal processing units ex507 that conform to therespective standards.

In order to solve the problem, what is conceived is a configuration inwhich the decoding processing unit for implementing the moving picturedecoding method described in each of embodiments and the decodingprocessing unit that conforms to the conventional standard, such asMPEG-2, MPEG-4 AVC, and VC-1 are partly shared. Ex900 in FIG. 35A showsan example of the configuration. For example, the moving picturedecoding method described in each of embodiments and the moving picturedecoding method that conforms to MPEG-4 AVC have, partly in common, thedetails of processing, such as entropy encoding, inverse quantization,deblocking filtering, and motion compensated prediction. The details ofprocessing to be shared probably include use of a decoding processingunit ex902 that conforms to MPEG-4 AVC. In contrast, a dedicateddecoding processing unit ex901 is probably used for other processingwhich is unique to an aspect of the present disclosure and does notconform to MPEG-4 AVC. Since the aspect of the present disclosure ischaracterized by scalable encoding in particular, for example, thededicated decoding processing unit ex901 is used for scalable encoding.Otherwise, the decoding processing unit is probably shared for one ofthe entropy decoding, inverse quantization deblocking filtering, andmotion compensation, or all of the processing. The decoding processingunit for implementing the moving picture decoding method described ineach of embodiments may be shared for the processing to be shared, and adedicated decoding processing unit may be used for processing unique tothat of MPEG-4 AVC.

Furthermore, ex1000 in FIG. 35B shows another example in that processingis partly shared. This example uses a configuration including adedicated decoding processing unit ex1001 that supports the processingunique to an aspect of the present disclosure, a dedicated decodingprocessing unit ex1002 that supports the processing unique to anotherconventional standard, and a decoding processing unit ex1003 thatsupports processing to be shared between the moving picture decodingmethod according to the aspect of the present disclosure and theconventional moving picture decoding method. Here, the dedicateddecoding processing units ex1001 and ex1002 are not necessarilyspecialized for the processing according to the aspect of the presentdisclosure and the processing of the conventional standard,respectively, and may be the ones capable of implementing generalprocessing. Furthermore, the configuration of the present embodiment canbe implemented by the LSI ex500.

As such, reducing the scale of the circuit of an LSI and reducing thecost are possible by sharing the decoding processing unit for theprocessing to be shared between the moving picture decoding methodaccording to the aspect of the present disclosure and the moving picturedecoding method in conformity with the conventional standard.

The herein disclosed subject matter is to be considered descriptive andillustrative only, and the appended Claims are of a scope intended tocover and encompass not only the particular embodiments disclosed, butalso equivalent structures, methods, and/or uses.

INDUSTRIAL APPLICABILITY

The video decoding method and apparatus or video encoding method andapparatus according to one or more exemplary embodiments disclosedherein are applicable to high-resolution information display devices orimage-capturing devices which include video decoding apparatuses, suchas a television, a digital video recorder, a car navigation system, acellular phone, a digital still camera, and a digital video camera.

The invention claimed is:
 1. A video encoding method of performingscalable encoding on video, the video encoding method comprising:determining, for the video, a total number of layers that is less thanor equal to a maximum layer count based on a frame rate of the video;and performing the scalable encoding on pictures included in the videoto generate a bitstream, using a layer structure including as manylayers as the total number of layers determined, wherein a shallowestlayer of the layers includes at least one picture, and the shallowestlayer includes no B-picture, the I-picture being an intra-frameprediction picture, the B-picture being a bi-directional referenceprediction picture.
 2. The video encoding method according to claim 1,wherein at least one B-picture is included in a layer other than theshallowest layer of the layers, and a P-picture is included in theshallowest layer, the P-picture being a forward reference predictionpicture.
 3. The video encoding method according to claim 1, wherein themaximum layer count is less than or equal to four when the frame rate isless than or equal to 60 frames per second (fps).
 4. The video encodingmethod according to claim 1, wherein the maximum layer count is fivewhen the frame rate is 120 fps.
 5. The video encoding method accordingto claim 1, further comprising determining a picture type of picturesincluded in the video from the I-picture, a P-picture, or the B-picture,to make a display latency picture count less than or equal to a maximumpicture count determined according to the frame rate, the displaylatency picture count being a total number of decoded pictures waitingfor being outputted in a video decoding apparatus, the P-picture being aforward reference prediction picture, wherein in the performing, thevideo is encoded as the pictures each having the picture typedetermined, and in the determining of a picture type, the picture typeof the pictures is determined from the I-picture, the P-picture, and theB-picture, to make a continuous B-picture count less than or equal to amaximum continuous count determined according to the frame rate, thecontinuous B-picture count being a total number of continuousbi-directional reference prediction pictures.
 6. The video encodingmethod according to claim 5, wherein the maximum picture count, anencoder output latency from when the video is input to a video encodingapparatus to when the bitstream is output, and the frame rate aredefined byMaximum picture count=int(log₂(encoder output latency [s]×frame rate[fps])), the maximum continuous count, the encoder output latency, andthe frame rate are defined byMaximum continuous count=int(encoder output latency [s]×frame rate[fps]−1), and the maximum layer count, the encoder output latency, andthe frame rate are defined byMaximum layer count=int(log₂(encoder output latency [s]×frame rate[fps]))+1.
 7. The video encoding method according to claim 6, wherein amaximum picture count [i] in each layer, the encoder output latency, andthe frame rate are defined byMaximum picture count [i]=int(log₂(encoder output latency [s]×frame rate[fps]/2^((n-i)))), and a maximum continuous count [i] in each layer, theencoder output latency, and the frame rate are defined byMaximum continuous count [i]=int(encoder output latency [s]×frame rate[fps]/2^((n-i))−1) where i is an integer less than or equal to themaximum layer count and represents a layer, and n represents (themaximum layer count−1).
 8. A video decoding method of decoding abitstream obtained by performing scalable encoding on pictures includedin a video using a layer structure including as many layers as a totalnumber of layers, the video decoding method comprising: decoding thepictures in the bitstream; decoding first information in the bitstream,the first information indicating the total number of layers; andreordering, using the total number of layers indicated in the firstinformation, the pictures included in the video decoded, and outputtingthe pictures reordered, wherein the total number of layers is less thanor equal to a maximum layer count predetermined according to a framerate of the bitstream of the video, and a shallowest layer of the layersincludes at least an I-picture, the shallowest layer includes noB-picture, the I-picture being an intra-frame prediction picture, theB-picture being a bi-directional reference prediction picture.
 9. Thevideo decoding method according to claim 8, wherein at least oneB-picture is included in a layer other than the shallowest layer of thelayers, and a P-picture is included in the shallowest layer, theP-picture being a forward reference prediction picture.
 10. The videodecoding method according to claim 8, wherein the maximum layer count isless than or equal to four when the frame rate is less than or equal to60 fps.
 11. The video decoding method according to claim 8, wherein themaximum layer count is five when the frame rate is 120 fps.
 12. Thevideo decoding method according to claim 8, wherein further in thedecoding of first information, second information in the bitstream isdecoded, the second information indicating a display latency picturecount which is a total number of decoded pictures waiting for beingoutputted in a video decoding apparatus, and in the reordering, thepictures included in the video decoded are reordered using the totalnumber of layers indicated in the first information and the displaylatency picture count indicated in the second information, and thepictures reordered are output.
 13. The video decoding method accordingto claim 12, wherein further in the decoding of first information, thirdinformation in the bitstream is decoded, the third informationindicating a continuous B-picture count which is a total number ofcontinuous bi-directional prediction pictures, and in the reordering,the pictures included in the video decoded are reordered using the totalnumber of layers indicated in the first information, the display latencypicture count indicated in the second information, and the continuousB-picture count indicated in the third information, and the picturesreordered are output.
 14. The video decoding method according to claim13, wherein a maximum picture count determined according to the framerate, an encoder output latency from when the video is input to a videoencoding apparatus to when the bitstream is output, and the frame rateare defined byMaximum picture count=int(log₂(encoder output latency [s]×frame rate[fps])), a maximum continuous count determined according to the framerate, the encoder output latency, and the frame rate are defined byMaximum continuous count=int(encoder output latency [s]×frame rate[fps]−1), and the maximum layer count, the encoder output latency, andthe frame rate are defined byMaximum layer count=int(log₂(encoder output latency [s]×frame rate[fps]))+1.
 15. The video decoding method according to claim 14, whereina maximum picture count [i] in each layer, the encoder output latency,and the frame rate are defined byMaximum picture count [i]=int(log₂(encoder output latency [s]×frame rate[fps]/2^((n-i)))), and a maximum continuous count [i] in each layer, theencoder output latency, and the frame rate are defined byMaximum continuous count [i]=int(encoder output latency [s]×frame rate[fps]/2^((n-i))−1) where i is an integer less than or equal to themaximum layer count and represents a layer, and n represents (themaximum layer count−1).
 16. A video encoding apparatus that encodesvideo, the video encoding apparatus comprising: processing circuitry;and storage accessible from the processing circuitry, wherein using thestorage, the processing circuitry performs the video encoding methodaccording to claim
 1. 17. A video decoding apparatus that decodes abitstream obtained by encoding video, the video decoding apparatuscomprising: processing circuitry; and storage accessible from theprocessing circuitry, wherein using the storage, the processingcircuitry performs the video decoding method according to claim 8.